/* ==========================================================================
   responsive.css — 响应式样式（移动端优先适配）
   断点：≤768 移动端 | 769–1024 平板 | ≥1025 桌面
   ========================================================================== */

/* --------------------------------------------------------------------------
   平板 (≤1024px)
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
  .grid--4 { grid-template-columns: repeat(3, 1fr); }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .carousel__slide { min-height: 320px; }
}

/* --------------------------------------------------------------------------
   导航折叠为汉堡菜单 (≤1400px)
   导航频道较多（含英文长词），为保证中英文都整齐不挤压，空间不足时收起为菜单
   -------------------------------------------------------------------------- */
@media (max-width: 1400px) {
  .nav-toggle { display: flex; }
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    z-index: 99;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-line);
    box-shadow: var(--shadow-md);
    padding: 8px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease),
                visibility var(--dur);
  }
  .main-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  .main-nav a {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    white-space: normal;
  }
  .main-nav a.is-active::after { display: none; }
  .main-nav a.is-active { background: var(--color-bg-soft); }

  /* 头部按钮精简 */
  .header-actions .btn { padding: 8px 16px; font-size: 0.85rem; }
}

/* --------------------------------------------------------------------------
   移动端 (≤768px)
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  :root { --header-h: 60px; }

  .container { padding-inline: 18px; }

  /* 英文版品牌名较长，移动端收紧避免头部横向溢出 */
  html[lang="en"] .brand__name { font-size: 0.9rem; letter-spacing: 0.02em; }
  html[lang="en"] .brand { gap: 6px; }
  html[lang="en"] .header-actions { gap: 6px; }
  html[lang="en"] .header-actions .btn--sm { padding: 6px 10px; font-size: 0.78rem; }

  /* 栅格 */
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: 1fr; }
  .grid { gap: 18px; }

  /* 区块标题 */
  .section-head { margin-bottom: 20px; }
  .section-sub { display: none; }

  /* 轮播 */
  .carousel__slide { min-height: 300px; }
  .carousel__slide-inner { padding: 32px 28px; }
  .carousel__dots { left: 28px; bottom: 20px; }
  .carousel__arrow { display: none; }
  .carousel__desc { font-size: 0.9rem; }

  /* 页脚 */
  .footer-grid { grid-template-columns: 1fr; gap: 28px; padding: 44px 0 28px; }
  .footer-bottom { flex-direction: column; text-align: center; gap: 8px; }

  /* 评论 */
  .comment__imgs img { width: 68px; height: 68px; }

  /* 弹窗 */
  .modal { padding: 16px; }

  .site-footer { margin-top: 48px; }
}

/* --------------------------------------------------------------------------
   小屏手机 (≤420px)
   -------------------------------------------------------------------------- */
@media (max-width: 420px) {
  .chip { padding: 7px 16px; font-size: 0.85rem; }
  .input-group { flex-direction: column; }
}

/* --------------------------------------------------------------------------
   桌面端 (≥1025px)
   -------------------------------------------------------------------------- */
@media (min-width: 1025px) {
  .grid--5 { grid-template-columns: repeat(5, 1fr); }
}

/* 动效偏好：用户减弱动画时禁用 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}